I have no interest in the Plus, but I'm definitely happy about the 128GB regular model. I keep my entire music library on my 64GB iPhone 4S which is 31GB all by itself. Add apps, games, pictures, and videos and things can get crowded pretty quickly.
That's why, despite certain Anandtech editor's protestations, some people think MicroSD cards are rather useful. My 2 year old Galaxy S3 has a 64GB MicroSD card at the moment. If I want more storage I can just get a 128GB card instead, and put more music/videos/etc on it as I want.
And 128GB MicroSD didn't even exist 2 years ago.
Would be nice if all phones had it. Never going to happen with Apple, but even most non-Apple manufacturers started to phase MicroSD out of high end phones, while increasing specs.